CD43 Epitopes are Differentially Expressed on Murine B and T Lymphocytes The murine CD43 antigen (Leukosialin) is a heavily glycosylated molecule encoded by a single gene. It is thought to play a role in adhesion, although its specific role has not yet been defined. The present study using monoclonal antibodies has established that isoforms of leukosialin are differentially expressed on B and T cell populations. The meaning at this differential expression is presently unclear, but further experiments will examine isoform expression related to lymphocyte cell cycle, cognate B and T cell interaction, intracellular signalling, and patterns of glycosylation of the molecule. KEY WORDS: Leukosialin, adhesion molecules, monoclonal antibodies